<template>
  <div>message的值：{{ message }}</div>
  <div>obj.message的值：{{ obj.message }}</div>
</template>

<script setup>
import { reactive, toRef } from 'vue'
const obj = reactive({ message: '黑发不知勤学早，白首方悔读书迟' })
const message = toRef(obj, 'message')
setTimeout(() => {
  message.value = '少壮不努力，老大徒伤悲'
}, 2000)
</script>
 